It has been known for some time now that methods for producing dental restoration parts may be improved by determining the chroma and brightness values of neighboring teeth adjacent to the tooth to be restored, and are used as a model, also with respect to the local distribution, for the dental restoration part. Typically, the teeth are produced in different tooth colors wherein color sample denotations or “tooth colors” such as A2, B3 etc., are commonly used and set the tooth both with respect to brightness and the base color.
While an optical comparison by, for example, a color key or shade guide was traditionally conducted, as it is known from DE 10 2007 035 610 A1 and corresponding US published application No. 20090033927, which is hereby incorporated by reference, it has also been known for some time now to dentally realize said color key or shade guide and to refine or improve the choice of color by using a digital image of the neighboring tooth. In this connection EP 2 259 034 A1 and corresponding US published application No. 20100303315, which is hereby incorporated by reference, disclose a dental color key or shade guide and how to improve the tooth color of the replacement tooth with electronic support.
It has also already been proposed to further analyze the detected image of the neighboring tooth by rasterizing or scanning thereof and by dividing it into sections whose individual color and brightness values are determined in order to thus improve the distribution of the color and brightness values across the tooth.
Especially in the front tooth area the methods proposed so far, however, do not lead to optimal results, and the result strongly depends on the skill of the dental technician involved to define a harmonic coloring of the replacement tooth, i.e., the dental restoration part.